Syringes already filled with an aqueous-based drug solution play an increasingly important role in the pharmaceutical industry and the medical community. Within the industry community, these pre-filled syringes represent a market share of over $2 billion dollars, with over 60 products on the market and a growing number of protein-based products expected to enter the market in the near future.
From a medical standpoint, pre-filled syringes allow for improved drug delivery that is less wasteful, safer, and frequently easy enough for patients to do without the oversight of a medical professional.
An important part of the syringe is the plunger system, which relies on a layer of lubricant to allow for an ideal glide force and ensuring complete delivery of the drug product within the specific injection time and force.
The most common lubricant is silicone-based oil, and the siliconization of these syringes, understandably has played an important part in the development of pre-filled syringes. As well as providing an ideal glide force and ensuring that the plunger travels the full path, siliconization also provides several advantages. It is a hydrophobic oil allowing for easy emptying of a drug product, and an oil that is low reacting, frequently used as a buffer layer between the syringe barrel and the drug product ensuring no reaction takes place between the two materials.
For sensitive applications, such as injections into the human eye for treatment, silicone oil droplets are observable within patients with an unknown amount of resulting damage.
As the FDA and other governing bodies work to eliminate the danger of these and other leachables, it is important to develop technology that will provide for the establishment of a stable lubricant layer on the interior of the syringe barrel.